Filter bag



c. E. MEYERHQEFER 2,848,062

FILTER BAG Original Filed April 22. 1954 Aug. 19, 1958 lNVENTOR ATTORNEYS United States Patent O FILTER BAG Carl E. Meyerhoefer, Little Neck, N. Y., assignor to Lewyt Corporation, Long Island City, N. Y., a corporation of New York Original application April 22, 1954, Serial No. 424,887,

now Patent No. 2,792,076, dated May 14, 1957. Divided and this application March 8, 1957, Serial No. 644,771

1 Claim. (Cl. 18S-51) This invention relates to a structurally and functionally improved filter bag and especially a unit intended for use in connection with vacuum cleaners; the present invention also teaching a novel combination of filter bag structure and such vacuum cleaners.

The present application is a division of my earlier application for patent, Serial No. 424,887 on Filter Bag, filed in the U. S. Patent Office on April 22, 1954, now Patent No. 2,792,076.

-It is Van object `of the invention to furnish a unit of this, `type by means of which penetration of its body or wall by the high velocity impingement of dirt particles thereagainst, will be prevented.

Still another object is that of designing a filter which will be less susceptible to weakening and rupturing than heretofore and which may be economically manufactured by quantity production machinery and methods at less cost than air-pervious bags as heretofore designed.

With these and otherobjects in mind, reference is had to the attached sheet of drawings illustrating practical embodiments of the invention and in which:

Fig. 1 is a sectional side view taken `through a portion f a vacuum cleaner assembly `and showing one form of the present filter bag in association therewith;

Fig. 2 is a face View of that bag;

Fig. 3 is a perspective view` of the completed bag, with a portion of the lsame broken away to disclose underlying construction; and

Fig. 4 is a somewhat diagrammatic View showing an alternative structure.

Referring primarily to lFig. l, the numeral indicates the upper casing portion of a vacuum cleaner assembly which is closed by a lid 11 conveniently mounted by a hinge (not shown). Disposed within this Ilid is a disktype filter 12 of air pervious material. The general construction involved is rsubstantially identical with that disclosed in United States Patent 2,716,465, dated August 30, 1955. 1

As taught in that patent, the upper casing portion 10 encloses an imperforate trough having an open upper face and side walls 13 spaced from the inner face of the casing walls. Due to the spacing, passages for the flow of air are present. The base of this trough, as indicated -at 14, may include an upwardly bulged or pedestal portion. Below this, a motor blower unit 1S is disposed.

As also disclosed in the prior patent, a coupling for a hose 16 is provided in association 4with casing portion 10. The latter mounts in line with the opening defined by this collar or coupling, a deflector shield 17, the base of which may be circular in section and the inner end of which terminates in a downwardly and inwardly opening hood. A bag of air-porous paper is disposed within trough 13 and includes a body 18. The latter is formed with an opening adjacent its forward end 'and which opening is defined by a collar 19. This collar encircles the fitting or inlet unit 17 in the manner shown in Fig. 1.

Under these circumstances, and with the motor blower unit 15 operating, dust-laden air will be drawn through the hose coupling and deflector 17 into the interior of the bag`18. Therefore, as indicated, dust-laden particles 'will be directed against the inner face of the base portion or lower surface of the bag as shown in -this figure. In that area, the bag is supported by the upwardly bulged part 14 of the trough, if such structure be included in the assembly. The air wil-l distend the bag so that it substantially fills the trough with its rear end braced :against the adjacent surface of the latter and its upper surface bearing against parts of the filter `assembly 12.

Even if the base portion of the trough be corrugated,

a minimum amount of filtered air will pass through the adjacent bag wall, although the latter be formed of airporous paper. Rather, the greatest amount of the air will move upwardly through the bag in the direction of filter 12. Thereupon, it will pass t-hrough the bag wall and the filter assembly 12 and reverse its course to dow between the inner face of casing section 10 and trough 13 toward the motor blower unit. From the latter, it will be dis-charged through a suitable outlet or outlets as disclosed in my prior patent. It is found that in the case of air-porous paper providing the surface against which the dust particles impin-ge upon their entrance into the bag and due to the velocity of particle movement they are forced through the paper. rFhis will occur throughout the area indicated by the flow lines in Fig. l. Upon the bag being filled and removed, the adjacent base portion 14 of the trough will be covered lwith ysuch particles.

yBy means of the present teachings, this objectionable result is avoided. More particularly and as shown in Figs. 2 and 3, the outer end of the bag may be defined by a square area 20, centrally of 'which collar 19 is mounted by having its flange glued or otherwise secured adjacent the bag opening. The side walls 21 of the bag extend from the rectangular Iend thereof and terminate in a base portion 22, `within which there may be incorporated a suitable number of folds 23 to provide a seal at this point. The side walls 21 include `an upper part 21a and a lower part 2lb. All of these parts are generally manufactured of air-pervious paper with the exception only of collar 19.

However, as shown in Figs. l to 3, a layer 24 of relatively hard, abrasion-resisting material is applied to the inner face of one of the side walls 21, with its end edges spaced from `the base 22 and the outer end 20. This layer is preferably formed of air-impervious paper and is secured in position by glue. Specifically it may be made of kraft paper, which embodies the desired characteristics and which costs only a lfraction per pound of yairapervious paper, providing the remainder of the bag body.

The material of the outer bag end 20 is preferably continued within the area deiined by collar 19. A slit, or transverse line of weakening 26 extends across this space. Ar-cuate slits, or weakening lines 27 are also provided extending from the line 26, adjacent the inner collar surface through to points short of each other to furnish flaps 25 permanently connected to the bag body by what might be termed hinge portions.

-It follows as a consequence of this structure, the application of the bag lto the fixture or deflector 17, will result in the end wall of the bag opening along the lines of 4weakening 26 and 27. In effect, iiaps 25 will thus be furnished which remain integrally united with the bag body. The collar 19 and its associated flange being wholly outside of the bag, it is apparent that they will not interfere `with the hinging or swinging action of the flaps. Accordingly, no interference with incoming dustladen air will occur incident to the use of these flapswhich when the bag is mounted-'will be swung to wholly open positions. However, with cover 11 swung up- Patented Aug. 19, 1958l wardly, the bag may be removed by simply withdrawing collar 19 over the fixture 17. With that action, air land the mass of foreign material l(dust, dirt particles, etc.) will be subjected to `a slightcompressive,action `resulting in the flaps shifting outwardlytolpositions at=which they aresubstantially co-extensivewiththe outerrend 20. Thus, they' will function vas acheck valvelstructurettoi/prevent'an lescapeof dust and dirtZ particles from'therbag interior as the latter is removed from trough13and subsequently disposed of.

It `will'be observed'inconnection with-the strip -.of impervious material that the ybagis-rnounted within'the trough to have thisstrip lie in contact with the base portion 14 of that lunit, -witha fixture .or defiector 17 of the typel shown and-described. Therefore, incoming air laden with foreign -materialywillbedeflected downwardly onto lthe ysurface lofstrip 24. The-.particles'of foreign materia-l will, -under theselciroumstances, sirnpjly rebound from the surface-of that strip. Due to the character of the latter,-norimpingement betweentheseiparticles and the Istrip will occursuch that thedustparticles are forced through or intothe paper. At the same time, the filteringaction of` the bag will notbeimpairedbecause the` amount of -f airnormally passingbetween its lower surface `(when in appliedposition) and the-base14 of the trough is-of minimum volume. `It followswthat when the bagfis removed 'from the trough, thelatter will be left in completely clean condition with no dirt discoloration appearing onthe innerfsurface'of the trough base.

As will be understood--bysthose conversantv with bagmaking machines, the cost of manufacture in applying a separate strip 24--to bc incorporated infthebodyof the bag will not, `in effect, vbe -in-creasedover'a bag infr which `all sidey walls'are of-the-same1gauge1and -materialiand integral With each other. However, the cost of material such as kraft paper is only fractional'in-comparison with proper air-porouspaper. Therefore,y with a large ;quantity of bags involved, the over-all cost of manufacture will be materially reduced. The-:same results of lackof penetration of the bag bodyrfby. dirtv particles'may, of course, be achieved by constructionsfother than that illustrated in Figs. 1, 2 and 3.

For example, if in lieu ofthe deilectorV 1.7, ya fitting such as 28 is employed-as in Fig. 4-a discharge of. the-dirtladen air will occur into the bag=along thepath :indicated in that figure. As shown-this -will betowards theA inner face of the base portionl of that receptacle. Wherev such a path is involved, thatrareaof the bag need not include la fold zone 23 of `the nature shown in the earlierfigures. Rather, the base may be defined by-a simple -overlap of the adjacent terminal `areas 29'and 30 of the vbagy base. The facing surfaces of these Ilayers maybe adhesively secured -to each other. Whetheri they are, or not, Athey will be overlain by a layer 31 of material corresponding to layer 24. So-disposed and `secured to parts129 and 30 by adhesive, layer 31 will serveto maintain those .parts against separation. Obviously, it will protect them from perforation or damage by contact with abrasive particles.

It is preferred that layer 24 or 31 be sufficiently thin to be quite flexible. In thismanner it will not prevent the bag from being rolled up, or folded to assume a compact configuration for'purposes vofstorage or packaging. The layer-in every instance-will be in face-to-face contact with the adjacentusurfacefof the air-porous paper and the intervening adhesive may extend .throughout the entire area of contact.

Thus, among others,the several'objects of the inventionas-specically aforenoted areachieved. Obviously numerous changes in construction and rearrangements of the parts might be resorted to without departing from the `spirit of the inventionfasdened by the claim.

`I claim:

F or use with a vacuum cleanerl having a Icompartment defined by `a rigid `wall to accommodate .and support la filter bag to bediscarded after ithas once been filled/with dust and similar material, a bag including a body.formed of air-pervious paper of single.thicknessthroughout at least the :major portion Iof .thebag body,.said body having side walls formed of said. paper, said side walls including an upper partiand a lower part, a layer of air-impervious kraft paper overlying a portion of the inner face of said lower part, `said .layer being more. resistant to abrasion yby 'saiddust and similar materialthan'said air-pervious paper, said layer being adhesively secured..to said body in substantially face-to-face contact, the inner. confines of said vbag as defined by said body beingsubstantially` free from any obstructing means-except said layer, a `substantially rectangular outer end and base forming aV partof said bag :and separated from each other by said side Walls, said layer having end edges lspacedfrom saidouter' end, the base 0f said bag including a zone 4having `edge portions secured against separation from each-other, a collar having an opening. therethrough .and extending laterally `from said outer end, :said outerend having zones thereof cooperable to provide a pair of integrally hinged flaps adjacent said collar and normally closing thecollar opening and further being pivotable'away from `eachother-to a position within the confines of said bag as defined by said body, and.each of said hingedflaps being. formedof said air pervious paper and havingan axis and further being pivotable away from the other of. said `flaps about its axis, and the axis of each of said Iflaps being disposed lsubstantially normal to said lower part. of said side walls.

References Cited in the file of this patent UNITED STATES PATENTS 

